In many different installations, such as printing plants, textile plants, etc., it is necessary to transport large rolls of web material from one station to another. For example, in printing plants, it is necessary to transport rolls of paper from receiving pallets to the printing presses. Such rolls usually weigh more than 100 pounds, typically several-hundred pounds, and often are desirably transported individually, rather than in groups (i.e., with a fork lift). Therefore, it is desirable to provide a piece of equipment that allows one worker to easily, yet safely, transport a roll from one position to another.
According to the present invention a mechanism, and method, are provided which allow a single worker to easily, yet safely, transport rolls of webbed material weighing more than 100 pounds from one location to another. According to one aspect of the present invention, a pallet jack is provided for capturing and transporting a roll. The pallet comprises: A frame including first and second elongated in a first dimension, substantially parallel support arms spaced from each other in a second dimension generally transverse to the first dimension; the arms having first and second ends. First wheel means operatively mounted to the frame adjacent the second ends of the arms. A handle mounted to the frame adjacent the first wheel means. Second wheel means operatively mounted to the frame adjacent the first ends of the arms. Jack means for moving the second wheel means toward and away from the arms to elevate the arms when moved away from the arms. And, means for receiving a roll between the arms, the roll-receiving means comprising a cradle pivotally mounted to the arms and biasing means for biasing the cradle to a predetermined position with respect to the arms.
The cradle has a first end and a second end, the second end being closer to the handle than the first end. The cradle is pivotally mounted to the arms adjacent the first end thereof about a generally horizontal axis. The cradle has a roll-engaging surface and sidewalls extending upwardly from the roll-engaging surface. Preferably, the roll-engaging surface comprises first, second and third adjacent substantially planar surface portions, each making an obtuse angle with respect to one or more adjacent surface portions, the first surface portion adjacent the first end and the third surface portion adjacent the second end of the cradle. Also, at least one shock absorber is preferably mounted between the arms and the second end of the cradle to dampen movement of the cradle under the heavy weight of the roll.
The biasing means may comprise a gas spring mounted between the arms and the second end of the cradle for biasing the cradle second end toward a position in which the first surface portion thereof slopes upwardly in a direction from the second end toward the first end of the cradle. Also typically stop means are provided for stopping pivotal movement of the second end of the cradle against the bias of the biasing means after a predetermined amount of travel (e.g., after the cradle has pivoted roughly about 10.degree. to 15.degree. about its axis). Preferably, the cradle, arms, and biasing means are dimensioned and positioned so that when a roll of designed configuration is received by the cradle and the jack means elevates the arms, the first planar surface slopes downwardly in a direction extending from the first end of the cradle to the second end thereof. Also strap means are preferably provided mounted to the cradle sidewalls for strapping a roll to the cradle.
According to another aspect of the present invention, a roll-transporting mechanism is provided. The roll-transporting mechanism comprises the following elements: A frame including first and second substantially parallel support arms elongated in a first dimension and spaced from each other in a second dimension generally transverse to the first dimension, the arms having first and second ends. Wheel means operatively mounted to the frame for facilitating wheeled transport thereof. And means for receiving a roll between the arms, the roll receiving means comprising a rigid cradle pivotally mounted to the arms. The cradle has a first end and a second end, the second end of the cradle being closer to the arms second ends than the first end of the cradle is, and the cradle is pivotally mounted to the arms adjacent the first end thereof about a generally horizontal axis.
The invention also contemplates a method of transporting a roll of web (e.g., paper) material having a central hollow core and a weight of more than 100 pounds. The method comprises the steps of: (a) Ensuring that the jack has jacked up both ends of the arms. (b) Wheeling the mechanism into operative association with a roll of web material so that the roll is at the entry end of the cradle. (c) Rolling the roll into the cradle with the hollow core of the roll horizontal, the weight of the roll causing the cradle to pivot to a position in which the roll cannot spontaneously roll back out the entry end of the cradle. (d) Wheeling the mechanism to a position where the roll is desirably to be placed. (e) Lowering the arms to floor level allowing the cradle to pivot forward to a position in which the roll can be removed. And, (f) rolling the roll out of the cradle at the desired position.
The method according to the invention also preferably comprises the further step, between steps (c) and (d), of strapping the roll to the cradle by passing a strap attached to the cradle through core of the roll, and the still further step, prior to step (f), of unstrapping the roll. The method also preferably comprises the further step, between steps (d) and (e), of jacking down the arms so that they are in a substantially horizontal plane. In the practice of the method, the arms may be in a substantially horizontal plane during the practice of step (c).
It is the primary object of the present invention to provide a mechanism and method for easily and safely transporting a heavy roll within an industrial environment. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.